Effect of stocking density on the growth and survival of the critically endangered peninsular carp Hypselobarbus pulchellus (Day, 1870) in fingerling rearing

The present study was undertaken to generate first time information on the optimal stocking density for fry to fingerling rearing of Hypselobarbus pulchellus. Rearing was carried out for 90 days at stocking densities of 15, 30, 45, 60, 75, 90, 105 and 120 fish/m2 in 24 m2 cement tanks. While the length of fish at harvest ranged from 3.42 cm in 120/m2 to 6.11 cm in 15/m2 densities, the weight ranged from 0.41 g in 120/m2 to 2.62 g in 15/m2. The final length and weight were inversely related to the stocking density. However, no significant variation (p > 0.05) in length was observed among the stocking densities of 15, 30, 45 and 60/m2. Similarly, the final weight of the fingerlings also did not differ (p > 0.05) between the stocking densities 15, 30 and 45/m2. Further, increase in stocking densities resulted in significant reduction in final length and weight, with the highest stocking density of 120/m2 recording the lowest values. The condition factor varied between 0.95 and 1.17 with no difference (p > 0.05) among the stocking densities. The survival of fingerlings at harvest ranged between 81 and 90%, but was not statistically different. The growth in terms of length and weight of H. pulchellus was superior under stocking densities 15, 30 and 45 fish/m2 compared to higher densities. Hence, the stocking density of 45 fish /m2 is recommended as the optimum for fry to fingerling rearing of H. pulchellus.